The present invention relates to transdermal or transmucosal formulations, methods of use for preparing medicaments for treating hot flashes and methods for treatment thereof by administering such formulations for transdermal or transmucosal administration of estrogen. The formulations are effective at surprisingly low daily doses, preferably the lowest effective dose of estrogen to treat hot flashes, namely about 0.45 to about 0.6 mg of estrogen per day in a delivery vehicle that includes a C2 to C4 alkanol, a polyalcohol, and a permeation enhancer of monoalkyl ether of diethylene glycol. The amount of estrogen which is administered produces an estimated nominal daily estrogen dose in a subject undergoing treatment of from about 10 to about 15 micrograms, and a serum estradiol level of between about 25 pg/ml to about 50 pg/ml.
